Flow work

2. Name :
Rashid Ali Bugti
Mechanical engg

3. Topic:
Flow work and total energy of flowing
fluid with examples.

4. Flow Work
 Unlike closed systems, control volumes involve mass flow across their boundaries
 Some work is required to push the mass into or out of the control volume
 This is known as flow work, or flow energy.
.
Wflow = PV ... and on a mass basis ... wflow = Pv

6. Total energy of non-flowing fluid
 The total energy of a simple compressible system consists of three parts: internal,
kinetic, and potential energies.
 It is denoted by e.

7. EXAMPLE:

8. Total energy of flowing fluid
 The fluid entering or leaving a control volume possesses an additional
form of energy—the flow energy Pv.
 It is denoted by

9. EXAMPLE:

10. Reference:
Thermodynamics: An Engineering Approach, 5th edition
by Yunus A. Çengel and Michael A. Boles
Chapter 5 (5-2)